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(LDPC)和Logistic混沌加密技术提高正交频分复用(OFDM)信号在60 GHz光载无线通信(ROF)系统中的传输性能以及实现系统加密性.采用非规则长LDPC纠错编码用于降低光纤链路中的色散效应,利用Logistic序列对初始条件的敏感特性作为密钥,在物理层实现对OFDM-ROF系统数据进行加密传输.研究结果表明:2.5 Gb/s 64-QAM数据在下行链路传输了30 km标准单模光纤(SSMF),当误码率(BER)为1×10-3时,LDPC编码接收机灵敏度至少提高10 dB;解调端没有Logistic密钥,可得到误码星座图,验证了其加密性以及其较强的纠错能力和抗色散能力. 关键词:LDPC;Logistic序列;OFDM-ROF;64-QAM 中图分类号:TN914  ......
shaping. To show PAPR analysis of the proposed system, the data are generated randomly then modulated by QPSK, 16-QAM and 64-QAM respectively. The PAPR was evaluated statistically by using complementary... pulse shaping respectively, using 64-QAM modulation. It is observed that the proposed ZCMT precoding based system provides considerable PAPR gain for the OFDMA signal when compared to that of conventional......
coding (MLC) [15] scheme for 64-QAM modulation such that b-b1 are coded and b1 is left uncoded. Note that the proposed scheme relies on the soft-information of the detection/ decoding part, so any coding... with different levels of phase noise variances σ△. For 64-QAM modulation, an MLC scheme is adopted according to Ungerboeck set partitioning rules, and subsets are selected to maximize the Euclidean......